1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/sch_cbq.c Class-Based Queueing discipline.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 */
7
8 #include <linux/module.h>
9 #include <linux/slab.h>
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/errno.h>
14 #include <linux/skbuff.h>
15 #include <net/netlink.h>
16 #include <net/pkt_sched.h>
17 #include <net/pkt_cls.h>
18
19
20 /* Class-Based Queueing (CBQ) algorithm.
21 =======================================
22
23 Sources: [1] Sally Floyd and Van Jacobson, "Link-sharing and Resource
24 Management Models for Packet Networks",
25 IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995
26
27 [2] Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995
28
29 [3] Sally Floyd, "Notes on Class-Based Queueing: Setting
30 Parameters", 1996
31
32 [4] Sally Floyd and Michael Speer, "Experimental Results
33 for Class-Based Queueing", 1998, not published.
34
35 -----------------------------------------------------------------------
36
37 Algorithm skeleton was taken from NS simulator cbq.cc.
38 If someone wants to check this code against the LBL version,
39 he should take into account that ONLY the skeleton was borrowed,
40 the implementation is different. Particularly:
41
42 --- The WRR algorithm is different. Our version looks more
43 reasonable (I hope) and works when quanta are allowed to be
44 less than MTU, which is always the case when real time classes
45 have small rates. Note, that the statement of [3] is
46 incomplete, delay may actually be estimated even if class
47 per-round allotment is less than MTU. Namely, if per-round
48 allotment is W*r_i, and r_1+...+r_k = r < 1
49
50 delay_i <= ([MTU/(W*r_i)]*W*r + W*r + k*MTU)/B
51
52 In the worst case we have IntServ estimate with D = W*r+k*MTU
53 and C = MTU*r. The proof (if correct at all) is trivial.
54
55
56 --- It seems that cbq-2.0 is not very accurate. At least, I cannot
57 interpret some places, which look like wrong translations
58 from NS. Anyone is advised to find these differences
59 and explain to me, why I am wrong 8).
60
61 --- Linux has no EOI event, so that we cannot estimate true class
62 idle time. Workaround is to consider the next dequeue event
63 as sign that previous packet is finished. This is wrong because of
64 internal device queueing, but on a permanently loaded link it is true.
65 Moreover, combined with clock integrator, this scheme looks
66 very close to an ideal solution. */
67
68 struct cbq_sched_data;
69
70
71 struct cbq_class {
72 struct Qdisc_class_common common;
73 struct cbq_class *next_alive; /* next class with backlog in this priority band */
74
75 /* Parameters */
76 unsigned char priority; /* class priority */
77 unsigned char priority2; /* priority to be used after overlimit */
78 unsigned char ewma_log; /* time constant for idle time calculation */
79
80 u32 defmap;
81
82 /* Link-sharing scheduler parameters */
83 long maxidle; /* Class parameters: see below. */
84 long offtime;
85 long minidle;
86 u32 avpkt;
87 struct qdisc_rate_table *R_tab;
88
89 /* General scheduler (WRR) parameters */
90 long allot;
91 long quantum; /* Allotment per WRR round */
92 long weight; /* Relative allotment: see below */
93
94 struct Qdisc *qdisc; /* Ptr to CBQ discipline */
95 struct cbq_class *split; /* Ptr to split node */
96 struct cbq_class *share; /* Ptr to LS parent in the class tree */
97 struct cbq_class *tparent; /* Ptr to tree parent in the class tree */
98 struct cbq_class *borrow; /* NULL if class is bandwidth limited;
99 parent otherwise */
100 struct cbq_class *sibling; /* Sibling chain */
101 struct cbq_class *children; /* Pointer to children chain */
102
103 struct Qdisc *q; /* Elementary queueing discipline */
104
105
106 /* Variables */
107 unsigned char cpriority; /* Effective priority */
108 unsigned char delayed;
109 unsigned char level; /* level of the class in hierarchy:
110 0 for leaf classes, and maximal
111 level of children + 1 for nodes.
112 */
113
114 psched_time_t last; /* Last end of service */
115 psched_time_t undertime;
116 long avgidle;
117 long deficit; /* Saved deficit for WRR */
118 psched_time_t penalized;
119 struct gnet_stats_basic_packed bstats;
120 struct gnet_stats_queue qstats;
121 struct net_rate_estimator __rcu *rate_est;
122 struct tc_cbq_xstats xstats;
123
124 struct tcf_proto __rcu *filter_list;
125 struct tcf_block *block;
126
127 int filters;
128
129 struct cbq_class *defaults[TC_PRIO_MAX + 1];
130 };
131
132 struct cbq_sched_data {
133 struct Qdisc_class_hash clhash; /* Hash table of all classes */
134 int nclasses[TC_CBQ_MAXPRIO + 1];
135 unsigned int quanta[TC_CBQ_MAXPRIO + 1];
136
137 struct cbq_class link;
138
139 unsigned int activemask;
140 struct cbq_class *active[TC_CBQ_MAXPRIO + 1]; /* List of all classes
141 with backlog */
142
143 #ifdef CONFIG_NET_CLS_ACT
144 struct cbq_class *rx_class;
145 #endif
146 struct cbq_class *tx_class;
147 struct cbq_class *tx_borrowed;
148 int tx_len;
149 psched_time_t now; /* Cached timestamp */
150 unsigned int pmask;
151
152 struct hrtimer delay_timer;
153 struct qdisc_watchdog watchdog; /* Watchdog timer,
154 started when CBQ has
155 backlog, but cannot
156 transmit just now */
157 psched_tdiff_t wd_expires;
158 int toplevel;
159 u32 hgenerator;
160 };
161
162
163 #define L2T(cl, len) qdisc_l2t((cl)->R_tab, len)
164
165 static inline struct cbq_class *
cbq_class_lookup(struct cbq_sched_data * q,u32 classid)166 cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
167 {
168 struct Qdisc_class_common *clc;
169
170 clc = qdisc_class_find(&q->clhash, classid);
171 if (clc == NULL)
172 return NULL;
173 return container_of(clc, struct cbq_class, common);
174 }
175
176 #ifdef CONFIG_NET_CLS_ACT
177
178 static struct cbq_class *
cbq_reclassify(struct sk_buff * skb,struct cbq_class * this)179 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
180 {
181 struct cbq_class *cl;
182
183 for (cl = this->tparent; cl; cl = cl->tparent) {
184 struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT];
185
186 if (new != NULL && new != this)
187 return new;
188 }
189 return NULL;
190 }
191
192 #endif
193
194 /* Classify packet. The procedure is pretty complicated, but
195 * it allows us to combine link sharing and priority scheduling
196 * transparently.
197 *
198 * Namely, you can put link sharing rules (f.e. route based) at root of CBQ,
199 * so that it resolves to split nodes. Then packets are classified
200 * by logical priority, or a more specific classifier may be attached
201 * to the split node.
202 */
203
204 static struct cbq_class *
cbq_classify(struct sk_buff * skb,struct Qdisc * sch,int * qerr)205 cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
206 {
207 struct cbq_sched_data *q = qdisc_priv(sch);
208 struct cbq_class *head = &q->link;
209 struct cbq_class **defmap;
210 struct cbq_class *cl = NULL;
211 u32 prio = skb->priority;
212 struct tcf_proto *fl;
213 struct tcf_result res;
214
215 /*
216 * Step 1. If skb->priority points to one of our classes, use it.
217 */
218 if (TC_H_MAJ(prio ^ sch->handle) == 0 &&
219 (cl = cbq_class_lookup(q, prio)) != NULL)
220 return cl;
221
222 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
223 for (;;) {
224 int result = 0;
225 defmap = head->defaults;
226
227 fl = rcu_dereference_bh(head->filter_list);
228 /*
229 * Step 2+n. Apply classifier.
230 */
231 result = tcf_classify(skb, fl, &res, true);
232 if (!fl || result < 0)
233 goto fallback;
234
235 cl = (void *)res.class;
236 if (!cl) {
237 if (TC_H_MAJ(res.classid))
238 cl = cbq_class_lookup(q, res.classid);
239 else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL)
240 cl = defmap[TC_PRIO_BESTEFFORT];
241
242 if (cl == NULL)
243 goto fallback;
244 }
245 if (cl->level >= head->level)
246 goto fallback;
247 #ifdef CONFIG_NET_CLS_ACT
248 switch (result) {
249 case TC_ACT_QUEUED:
250 case TC_ACT_STOLEN:
251 case TC_ACT_TRAP:
252 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
253 fallthrough;
254 case TC_ACT_SHOT:
255 return NULL;
256 case TC_ACT_RECLASSIFY:
257 return cbq_reclassify(skb, cl);
258 }
259 #endif
260 if (cl->level == 0)
261 return cl;
262
263 /*
264 * Step 3+n. If classifier selected a link sharing class,
265 * apply agency specific classifier.
266 * Repeat this procdure until we hit a leaf node.
267 */
268 head = cl;
269 }
270
271 fallback:
272 cl = head;
273
274 /*
275 * Step 4. No success...
276 */
277 if (TC_H_MAJ(prio) == 0 &&
278 !(cl = head->defaults[prio & TC_PRIO_MAX]) &&
279 !(cl = head->defaults[TC_PRIO_BESTEFFORT]))
280 return head;
281
282 return cl;
283 }
284
285 /*
286 * A packet has just been enqueued on the empty class.
287 * cbq_activate_class adds it to the tail of active class list
288 * of its priority band.
289 */
290
cbq_activate_class(struct cbq_class * cl)291 static inline void cbq_activate_class(struct cbq_class *cl)
292 {
293 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
294 int prio = cl->cpriority;
295 struct cbq_class *cl_tail;
296
297 cl_tail = q->active[prio];
298 q->active[prio] = cl;
299
300 if (cl_tail != NULL) {
301 cl->next_alive = cl_tail->next_alive;
302 cl_tail->next_alive = cl;
303 } else {
304 cl->next_alive = cl;
305 q->activemask |= (1<<prio);
306 }
307 }
308
309 /*
310 * Unlink class from active chain.
311 * Note that this same procedure is done directly in cbq_dequeue*
312 * during round-robin procedure.
313 */
314
cbq_deactivate_class(struct cbq_class * this)315 static void cbq_deactivate_class(struct cbq_class *this)
316 {
317 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
318 int prio = this->cpriority;
319 struct cbq_class *cl;
320 struct cbq_class *cl_prev = q->active[prio];
321
322 do {
323 cl = cl_prev->next_alive;
324 if (cl == this) {
325 cl_prev->next_alive = cl->next_alive;
326 cl->next_alive = NULL;
327
328 if (cl == q->active[prio]) {
329 q->active[prio] = cl_prev;
330 if (cl == q->active[prio]) {
331 q->active[prio] = NULL;
332 q->activemask &= ~(1<<prio);
333 return;
334 }
335 }
336 return;
337 }
338 } while ((cl_prev = cl) != q->active[prio]);
339 }
340
341 static void
cbq_mark_toplevel(struct cbq_sched_data * q,struct cbq_class * cl)342 cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl)
343 {
344 int toplevel = q->toplevel;
345
346 if (toplevel > cl->level) {
347 psched_time_t now = psched_get_time();
348
349 do {
350 if (cl->undertime < now) {
351 q->toplevel = cl->level;
352 return;
353 }
354 } while ((cl = cl->borrow) != NULL && toplevel > cl->level);
355 }
356 }
357
358 static int
cbq_enqueue(struct sk_buff * skb,struct Qdisc * sch,struct sk_buff ** to_free)359 cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
360 struct sk_buff **to_free)
361 {
362 struct cbq_sched_data *q = qdisc_priv(sch);
363 int ret;
364 struct cbq_class *cl = cbq_classify(skb, sch, &ret);
365
366 #ifdef CONFIG_NET_CLS_ACT
367 q->rx_class = cl;
368 #endif
369 if (cl == NULL) {
370 if (ret & __NET_XMIT_BYPASS)
371 qdisc_qstats_drop(sch);
372 __qdisc_drop(skb, to_free);
373 return ret;
374 }
375
376 ret = qdisc_enqueue(skb, cl->q, to_free);
377 if (ret == NET_XMIT_SUCCESS) {
378 sch->q.qlen++;
379 cbq_mark_toplevel(q, cl);
380 if (!cl->next_alive)
381 cbq_activate_class(cl);
382 return ret;
383 }
384
385 if (net_xmit_drop_count(ret)) {
386 qdisc_qstats_drop(sch);
387 cbq_mark_toplevel(q, cl);
388 cl->qstats.drops++;
389 }
390 return ret;
391 }
392
393 /* Overlimit action: penalize leaf class by adding offtime */
cbq_overlimit(struct cbq_class * cl)394 static void cbq_overlimit(struct cbq_class *cl)
395 {
396 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
397 psched_tdiff_t delay = cl->undertime - q->now;
398
399 if (!cl->delayed) {
400 delay += cl->offtime;
401
402 /*
403 * Class goes to sleep, so that it will have no
404 * chance to work avgidle. Let's forgive it 8)
405 *
406 * BTW cbq-2.0 has a crap in this
407 * place, apparently they forgot to shift it by cl->ewma_log.
408 */
409 if (cl->avgidle < 0)
410 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log);
411 if (cl->avgidle < cl->minidle)
412 cl->avgidle = cl->minidle;
413 if (delay <= 0)
414 delay = 1;
415 cl->undertime = q->now + delay;
416
417 cl->xstats.overactions++;
418 cl->delayed = 1;
419 }
420 if (q->wd_expires == 0 || q->wd_expires > delay)
421 q->wd_expires = delay;
422
423 /* Dirty work! We must schedule wakeups based on
424 * real available rate, rather than leaf rate,
425 * which may be tiny (even zero).
426 */
427 if (q->toplevel == TC_CBQ_MAXLEVEL) {
428 struct cbq_class *b;
429 psched_tdiff_t base_delay = q->wd_expires;
430
431 for (b = cl->borrow; b; b = b->borrow) {
432 delay = b->undertime - q->now;
433 if (delay < base_delay) {
434 if (delay <= 0)
435 delay = 1;
436 base_delay = delay;
437 }
438 }
439
440 q->wd_expires = base_delay;
441 }
442 }
443
cbq_undelay_prio(struct cbq_sched_data * q,int prio,psched_time_t now)444 static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio,
445 psched_time_t now)
446 {
447 struct cbq_class *cl;
448 struct cbq_class *cl_prev = q->active[prio];
449 psched_time_t sched = now;
450
451 if (cl_prev == NULL)
452 return 0;
453
454 do {
455 cl = cl_prev->next_alive;
456 if (now - cl->penalized > 0) {
457 cl_prev->next_alive = cl->next_alive;
458 cl->next_alive = NULL;
459 cl->cpriority = cl->priority;
460 cl->delayed = 0;
461 cbq_activate_class(cl);
462
463 if (cl == q->active[prio]) {
464 q->active[prio] = cl_prev;
465 if (cl == q->active[prio]) {
466 q->active[prio] = NULL;
467 return 0;
468 }
469 }
470
471 cl = cl_prev->next_alive;
472 } else if (sched - cl->penalized > 0)
473 sched = cl->penalized;
474 } while ((cl_prev = cl) != q->active[prio]);
475
476 return sched - now;
477 }
478
cbq_undelay(struct hrtimer * timer)479 static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
480 {
481 struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data,
482 delay_timer);
483 struct Qdisc *sch = q->watchdog.qdisc;
484 psched_time_t now;
485 psched_tdiff_t delay = 0;
486 unsigned int pmask;
487
488 now = psched_get_time();
489
490 pmask = q->pmask;
491 q->pmask = 0;
492
493 while (pmask) {
494 int prio = ffz(~pmask);
495 psched_tdiff_t tmp;
496
497 pmask &= ~(1<<prio);
498
499 tmp = cbq_undelay_prio(q, prio, now);
500 if (tmp > 0) {
501 q->pmask |= 1<<prio;
502 if (tmp < delay || delay == 0)
503 delay = tmp;
504 }
505 }
506
507 if (delay) {
508 ktime_t time;
509
510 time = 0;
511 time = ktime_add_ns(time, PSCHED_TICKS2NS(now + delay));
512 hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS_PINNED);
513 }
514
515 __netif_schedule(qdisc_root(sch));
516 return HRTIMER_NORESTART;
517 }
518
519 /*
520 * It is mission critical procedure.
521 *
522 * We "regenerate" toplevel cutoff, if transmitting class
523 * has backlog and it is not regulated. It is not part of
524 * original CBQ description, but looks more reasonable.
525 * Probably, it is wrong. This question needs further investigation.
526 */
527
528 static inline void
cbq_update_toplevel(struct cbq_sched_data * q,struct cbq_class * cl,struct cbq_class * borrowed)529 cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl,
530 struct cbq_class *borrowed)
531 {
532 if (cl && q->toplevel >= borrowed->level) {
533 if (cl->q->q.qlen > 1) {
534 do {
535 if (borrowed->undertime == PSCHED_PASTPERFECT) {
536 q->toplevel = borrowed->level;
537 return;
538 }
539 } while ((borrowed = borrowed->borrow) != NULL);
540 }
541 #if 0
542 /* It is not necessary now. Uncommenting it
543 will save CPU cycles, but decrease fairness.
544 */
545 q->toplevel = TC_CBQ_MAXLEVEL;
546 #endif
547 }
548 }
549
550 static void
cbq_update(struct cbq_sched_data * q)551 cbq_update(struct cbq_sched_data *q)
552 {
553 struct cbq_class *this = q->tx_class;
554 struct cbq_class *cl = this;
555 int len = q->tx_len;
556 psched_time_t now;
557
558 q->tx_class = NULL;
559 /* Time integrator. We calculate EOS time
560 * by adding expected packet transmission time.
561 */
562 now = q->now + L2T(&q->link, len);
563
564 for ( ; cl; cl = cl->share) {
565 long avgidle = cl->avgidle;
566 long idle;
567
568 cl->bstats.packets++;
569 cl->bstats.bytes += len;
570
571 /*
572 * (now - last) is total time between packet right edges.
573 * (last_pktlen/rate) is "virtual" busy time, so that
574 *
575 * idle = (now - last) - last_pktlen/rate
576 */
577
578 idle = now - cl->last;
579 if ((unsigned long)idle > 128*1024*1024) {
580 avgidle = cl->maxidle;
581 } else {
582 idle -= L2T(cl, len);
583
584 /* true_avgidle := (1-W)*true_avgidle + W*idle,
585 * where W=2^{-ewma_log}. But cl->avgidle is scaled:
586 * cl->avgidle == true_avgidle/W,
587 * hence:
588 */
589 avgidle += idle - (avgidle>>cl->ewma_log);
590 }
591
592 if (avgidle <= 0) {
593 /* Overlimit or at-limit */
594
595 if (avgidle < cl->minidle)
596 avgidle = cl->minidle;
597
598 cl->avgidle = avgidle;
599
600 /* Calculate expected time, when this class
601 * will be allowed to send.
602 * It will occur, when:
603 * (1-W)*true_avgidle + W*delay = 0, i.e.
604 * idle = (1/W - 1)*(-true_avgidle)
605 * or
606 * idle = (1 - W)*(-cl->avgidle);
607 */
608 idle = (-avgidle) - ((-avgidle) >> cl->ewma_log);
609
610 /*
611 * That is not all.
612 * To maintain the rate allocated to the class,
613 * we add to undertime virtual clock,
614 * necessary to complete transmitted packet.
615 * (len/phys_bandwidth has been already passed
616 * to the moment of cbq_update)
617 */
618
619 idle -= L2T(&q->link, len);
620 idle += L2T(cl, len);
621
622 cl->undertime = now + idle;
623 } else {
624 /* Underlimit */
625
626 cl->undertime = PSCHED_PASTPERFECT;
627 if (avgidle > cl->maxidle)
628 cl->avgidle = cl->maxidle;
629 else
630 cl->avgidle = avgidle;
631 }
632 if ((s64)(now - cl->last) > 0)
633 cl->last = now;
634 }
635
636 cbq_update_toplevel(q, this, q->tx_borrowed);
637 }
638
639 static inline struct cbq_class *
cbq_under_limit(struct cbq_class * cl)640 cbq_under_limit(struct cbq_class *cl)
641 {
642 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
643 struct cbq_class *this_cl = cl;
644
645 if (cl->tparent == NULL)
646 return cl;
647
648 if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) {
649 cl->delayed = 0;
650 return cl;
651 }
652
653 do {
654 /* It is very suspicious place. Now overlimit
655 * action is generated for not bounded classes
656 * only if link is completely congested.
657 * Though it is in agree with ancestor-only paradigm,
658 * it looks very stupid. Particularly,
659 * it means that this chunk of code will either
660 * never be called or result in strong amplification
661 * of burstiness. Dangerous, silly, and, however,
662 * no another solution exists.
663 */
664 cl = cl->borrow;
665 if (!cl) {
666 this_cl->qstats.overlimits++;
667 cbq_overlimit(this_cl);
668 return NULL;
669 }
670 if (cl->level > q->toplevel)
671 return NULL;
672 } while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime);
673
674 cl->delayed = 0;
675 return cl;
676 }
677
678 static inline struct sk_buff *
cbq_dequeue_prio(struct Qdisc * sch,int prio)679 cbq_dequeue_prio(struct Qdisc *sch, int prio)
680 {
681 struct cbq_sched_data *q = qdisc_priv(sch);
682 struct cbq_class *cl_tail, *cl_prev, *cl;
683 struct sk_buff *skb;
684 int deficit;
685
686 cl_tail = cl_prev = q->active[prio];
687 cl = cl_prev->next_alive;
688
689 do {
690 deficit = 0;
691
692 /* Start round */
693 do {
694 struct cbq_class *borrow = cl;
695
696 if (cl->q->q.qlen &&
697 (borrow = cbq_under_limit(cl)) == NULL)
698 goto skip_class;
699
700 if (cl->deficit <= 0) {
701 /* Class exhausted its allotment per
702 * this round. Switch to the next one.
703 */
704 deficit = 1;
705 cl->deficit += cl->quantum;
706 goto next_class;
707 }
708
709 skb = cl->q->dequeue(cl->q);
710
711 /* Class did not give us any skb :-(
712 * It could occur even if cl->q->q.qlen != 0
713 * f.e. if cl->q == "tbf"
714 */
715 if (skb == NULL)
716 goto skip_class;
717
718 cl->deficit -= qdisc_pkt_len(skb);
719 q->tx_class = cl;
720 q->tx_borrowed = borrow;
721 if (borrow != cl) {
722 #ifndef CBQ_XSTATS_BORROWS_BYTES
723 borrow->xstats.borrows++;
724 cl->xstats.borrows++;
725 #else
726 borrow->xstats.borrows += qdisc_pkt_len(skb);
727 cl->xstats.borrows += qdisc_pkt_len(skb);
728 #endif
729 }
730 q->tx_len = qdisc_pkt_len(skb);
731
732 if (cl->deficit <= 0) {
733 q->active[prio] = cl;
734 cl = cl->next_alive;
735 cl->deficit += cl->quantum;
736 }
737 return skb;
738
739 skip_class:
740 if (cl->q->q.qlen == 0 || prio != cl->cpriority) {
741 /* Class is empty or penalized.
742 * Unlink it from active chain.
743 */
744 cl_prev->next_alive = cl->next_alive;
745 cl->next_alive = NULL;
746
747 /* Did cl_tail point to it? */
748 if (cl == cl_tail) {
749 /* Repair it! */
750 cl_tail = cl_prev;
751
752 /* Was it the last class in this band? */
753 if (cl == cl_tail) {
754 /* Kill the band! */
755 q->active[prio] = NULL;
756 q->activemask &= ~(1<<prio);
757 if (cl->q->q.qlen)
758 cbq_activate_class(cl);
759 return NULL;
760 }
761
762 q->active[prio] = cl_tail;
763 }
764 if (cl->q->q.qlen)
765 cbq_activate_class(cl);
766
767 cl = cl_prev;
768 }
769
770 next_class:
771 cl_prev = cl;
772 cl = cl->next_alive;
773 } while (cl_prev != cl_tail);
774 } while (deficit);
775
776 q->active[prio] = cl_prev;
777
778 return NULL;
779 }
780
781 static inline struct sk_buff *
cbq_dequeue_1(struct Qdisc * sch)782 cbq_dequeue_1(struct Qdisc *sch)
783 {
784 struct cbq_sched_data *q = qdisc_priv(sch);
785 struct sk_buff *skb;
786 unsigned int activemask;
787
788 activemask = q->activemask & 0xFF;
789 while (activemask) {
790 int prio = ffz(~activemask);
791 activemask &= ~(1<<prio);
792 skb = cbq_dequeue_prio(sch, prio);
793 if (skb)
794 return skb;
795 }
796 return NULL;
797 }
798
799 static struct sk_buff *
cbq_dequeue(struct Qdisc * sch)800 cbq_dequeue(struct Qdisc *sch)
801 {
802 struct sk_buff *skb;
803 struct cbq_sched_data *q = qdisc_priv(sch);
804 psched_time_t now;
805
806 now = psched_get_time();
807
808 if (q->tx_class)
809 cbq_update(q);
810
811 q->now = now;
812
813 for (;;) {
814 q->wd_expires = 0;
815
816 skb = cbq_dequeue_1(sch);
817 if (skb) {
818 qdisc_bstats_update(sch, skb);
819 sch->q.qlen--;
820 return skb;
821 }
822
823 /* All the classes are overlimit.
824 *
825 * It is possible, if:
826 *
827 * 1. Scheduler is empty.
828 * 2. Toplevel cutoff inhibited borrowing.
829 * 3. Root class is overlimit.
830 *
831 * Reset 2d and 3d conditions and retry.
832 *
833 * Note, that NS and cbq-2.0 are buggy, peeking
834 * an arbitrary class is appropriate for ancestor-only
835 * sharing, but not for toplevel algorithm.
836 *
837 * Our version is better, but slower, because it requires
838 * two passes, but it is unavoidable with top-level sharing.
839 */
840
841 if (q->toplevel == TC_CBQ_MAXLEVEL &&
842 q->link.undertime == PSCHED_PASTPERFECT)
843 break;
844
845 q->toplevel = TC_CBQ_MAXLEVEL;
846 q->link.undertime = PSCHED_PASTPERFECT;
847 }
848
849 /* No packets in scheduler or nobody wants to give them to us :-(
850 * Sigh... start watchdog timer in the last case.
851 */
852
853 if (sch->q.qlen) {
854 qdisc_qstats_overlimit(sch);
855 if (q->wd_expires)
856 qdisc_watchdog_schedule(&q->watchdog,
857 now + q->wd_expires);
858 }
859 return NULL;
860 }
861
862 /* CBQ class maintanance routines */
863
cbq_adjust_levels(struct cbq_class * this)864 static void cbq_adjust_levels(struct cbq_class *this)
865 {
866 if (this == NULL)
867 return;
868
869 do {
870 int level = 0;
871 struct cbq_class *cl;
872
873 cl = this->children;
874 if (cl) {
875 do {
876 if (cl->level > level)
877 level = cl->level;
878 } while ((cl = cl->sibling) != this->children);
879 }
880 this->level = level + 1;
881 } while ((this = this->tparent) != NULL);
882 }
883
cbq_normalize_quanta(struct cbq_sched_data * q,int prio)884 static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio)
885 {
886 struct cbq_class *cl;
887 unsigned int h;
888
889 if (q->quanta[prio] == 0)
890 return;
891
892 for (h = 0; h < q->clhash.hashsize; h++) {
893 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
894 /* BUGGGG... Beware! This expression suffer of
895 * arithmetic overflows!
896 */
897 if (cl->priority == prio) {
898 cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/
899 q->quanta[prio];
900 }
901 if (cl->quantum <= 0 ||
902 cl->quantum > 32*qdisc_dev(cl->qdisc)->mtu) {
903 pr_warn("CBQ: class %08x has bad quantum==%ld, repaired.\n",
904 cl->common.classid, cl->quantum);
905 cl->quantum = qdisc_dev(cl->qdisc)->mtu/2 + 1;
906 }
907 }
908 }
909 }
910
cbq_sync_defmap(struct cbq_class * cl)911 static void cbq_sync_defmap(struct cbq_class *cl)
912 {
913 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
914 struct cbq_class *split = cl->split;
915 unsigned int h;
916 int i;
917
918 if (split == NULL)
919 return;
920
921 for (i = 0; i <= TC_PRIO_MAX; i++) {
922 if (split->defaults[i] == cl && !(cl->defmap & (1<<i)))
923 split->defaults[i] = NULL;
924 }
925
926 for (i = 0; i <= TC_PRIO_MAX; i++) {
927 int level = split->level;
928
929 if (split->defaults[i])
930 continue;
931
932 for (h = 0; h < q->clhash.hashsize; h++) {
933 struct cbq_class *c;
934
935 hlist_for_each_entry(c, &q->clhash.hash[h],
936 common.hnode) {
937 if (c->split == split && c->level < level &&
938 c->defmap & (1<<i)) {
939 split->defaults[i] = c;
940 level = c->level;
941 }
942 }
943 }
944 }
945 }
946
cbq_change_defmap(struct cbq_class * cl,u32 splitid,u32 def,u32 mask)947 static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask)
948 {
949 struct cbq_class *split = NULL;
950
951 if (splitid == 0) {
952 split = cl->split;
953 if (!split)
954 return;
955 splitid = split->common.classid;
956 }
957
958 if (split == NULL || split->common.classid != splitid) {
959 for (split = cl->tparent; split; split = split->tparent)
960 if (split->common.classid == splitid)
961 break;
962 }
963
964 if (split == NULL)
965 return;
966
967 if (cl->split != split) {
968 cl->defmap = 0;
969 cbq_sync_defmap(cl);
970 cl->split = split;
971 cl->defmap = def & mask;
972 } else
973 cl->defmap = (cl->defmap & ~mask) | (def & mask);
974
975 cbq_sync_defmap(cl);
976 }
977
cbq_unlink_class(struct cbq_class * this)978 static void cbq_unlink_class(struct cbq_class *this)
979 {
980 struct cbq_class *cl, **clp;
981 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
982
983 qdisc_class_hash_remove(&q->clhash, &this->common);
984
985 if (this->tparent) {
986 clp = &this->sibling;
987 cl = *clp;
988 do {
989 if (cl == this) {
990 *clp = cl->sibling;
991 break;
992 }
993 clp = &cl->sibling;
994 } while ((cl = *clp) != this->sibling);
995
996 if (this->tparent->children == this) {
997 this->tparent->children = this->sibling;
998 if (this->sibling == this)
999 this->tparent->children = NULL;
1000 }
1001 } else {
1002 WARN_ON(this->sibling != this);
1003 }
1004 }
1005
cbq_link_class(struct cbq_class * this)1006 static void cbq_link_class(struct cbq_class *this)
1007 {
1008 struct cbq_sched_data *q = qdisc_priv(this->qdisc);
1009 struct cbq_class *parent = this->tparent;
1010
1011 this->sibling = this;
1012 qdisc_class_hash_insert(&q->clhash, &this->common);
1013
1014 if (parent == NULL)
1015 return;
1016
1017 if (parent->children == NULL) {
1018 parent->children = this;
1019 } else {
1020 this->sibling = parent->children->sibling;
1021 parent->children->sibling = this;
1022 }
1023 }
1024
1025 static void
cbq_reset(struct Qdisc * sch)1026 cbq_reset(struct Qdisc *sch)
1027 {
1028 struct cbq_sched_data *q = qdisc_priv(sch);
1029 struct cbq_class *cl;
1030 int prio;
1031 unsigned int h;
1032
1033 q->activemask = 0;
1034 q->pmask = 0;
1035 q->tx_class = NULL;
1036 q->tx_borrowed = NULL;
1037 qdisc_watchdog_cancel(&q->watchdog);
1038 hrtimer_cancel(&q->delay_timer);
1039 q->toplevel = TC_CBQ_MAXLEVEL;
1040 q->now = psched_get_time();
1041
1042 for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++)
1043 q->active[prio] = NULL;
1044
1045 for (h = 0; h < q->clhash.hashsize; h++) {
1046 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1047 qdisc_reset(cl->q);
1048
1049 cl->next_alive = NULL;
1050 cl->undertime = PSCHED_PASTPERFECT;
1051 cl->avgidle = cl->maxidle;
1052 cl->deficit = cl->quantum;
1053 cl->cpriority = cl->priority;
1054 }
1055 }
1056 sch->q.qlen = 0;
1057 }
1058
1059
cbq_set_lss(struct cbq_class * cl,struct tc_cbq_lssopt * lss)1060 static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss)
1061 {
1062 if (lss->change & TCF_CBQ_LSS_FLAGS) {
1063 cl->share = (lss->flags & TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent;
1064 cl->borrow = (lss->flags & TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent;
1065 }
1066 if (lss->change & TCF_CBQ_LSS_EWMA)
1067 cl->ewma_log = lss->ewma_log;
1068 if (lss->change & TCF_CBQ_LSS_AVPKT)
1069 cl->avpkt = lss->avpkt;
1070 if (lss->change & TCF_CBQ_LSS_MINIDLE)
1071 cl->minidle = -(long)lss->minidle;
1072 if (lss->change & TCF_CBQ_LSS_MAXIDLE) {
1073 cl->maxidle = lss->maxidle;
1074 cl->avgidle = lss->maxidle;
1075 }
1076 if (lss->change & TCF_CBQ_LSS_OFFTIME)
1077 cl->offtime = lss->offtime;
1078 return 0;
1079 }
1080
cbq_rmprio(struct cbq_sched_data * q,struct cbq_class * cl)1081 static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl)
1082 {
1083 q->nclasses[cl->priority]--;
1084 q->quanta[cl->priority] -= cl->weight;
1085 cbq_normalize_quanta(q, cl->priority);
1086 }
1087
cbq_addprio(struct cbq_sched_data * q,struct cbq_class * cl)1088 static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl)
1089 {
1090 q->nclasses[cl->priority]++;
1091 q->quanta[cl->priority] += cl->weight;
1092 cbq_normalize_quanta(q, cl->priority);
1093 }
1094
cbq_set_wrr(struct cbq_class * cl,struct tc_cbq_wrropt * wrr)1095 static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr)
1096 {
1097 struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
1098
1099 if (wrr->allot)
1100 cl->allot = wrr->allot;
1101 if (wrr->weight)
1102 cl->weight = wrr->weight;
1103 if (wrr->priority) {
1104 cl->priority = wrr->priority - 1;
1105 cl->cpriority = cl->priority;
1106 if (cl->priority >= cl->priority2)
1107 cl->priority2 = TC_CBQ_MAXPRIO - 1;
1108 }
1109
1110 cbq_addprio(q, cl);
1111 return 0;
1112 }
1113
cbq_set_fopt(struct cbq_class * cl,struct tc_cbq_fopt * fopt)1114 static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt)
1115 {
1116 cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange);
1117 return 0;
1118 }
1119
1120 static const struct nla_policy cbq_policy[TCA_CBQ_MAX + 1] = {
1121 [TCA_CBQ_LSSOPT] = { .len = sizeof(struct tc_cbq_lssopt) },
1122 [TCA_CBQ_WRROPT] = { .len = sizeof(struct tc_cbq_wrropt) },
1123 [TCA_CBQ_FOPT] = { .len = sizeof(struct tc_cbq_fopt) },
1124 [TCA_CBQ_OVL_STRATEGY] = { .len = sizeof(struct tc_cbq_ovl) },
1125 [TCA_CBQ_RATE] = { .len = sizeof(struct tc_ratespec) },
1126 [TCA_CBQ_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
1127 [TCA_CBQ_POLICE] = { .len = sizeof(struct tc_cbq_police) },
1128 };
1129
cbq_opt_parse(struct nlattr * tb[TCA_CBQ_MAX+1],struct nlattr * opt,struct netlink_ext_ack * extack)1130 static int cbq_opt_parse(struct nlattr *tb[TCA_CBQ_MAX + 1],
1131 struct nlattr *opt,
1132 struct netlink_ext_ack *extack)
1133 {
1134 int err;
1135
1136 if (!opt) {
1137 NL_SET_ERR_MSG(extack, "CBQ options are required for this operation");
1138 return -EINVAL;
1139 }
1140
1141 err = nla_parse_nested_deprecated(tb, TCA_CBQ_MAX, opt,
1142 cbq_policy, extack);
1143 if (err < 0)
1144 return err;
1145
1146 if (tb[TCA_CBQ_WRROPT]) {
1147 const struct tc_cbq_wrropt *wrr = nla_data(tb[TCA_CBQ_WRROPT]);
1148
1149 if (wrr->priority > TC_CBQ_MAXPRIO) {
1150 NL_SET_ERR_MSG(extack, "priority is bigger than TC_CBQ_MAXPRIO");
1151 err = -EINVAL;
1152 }
1153 }
1154 return err;
1155 }
1156
cbq_init(struct Qdisc * sch,struct nlattr * opt,struct netlink_ext_ack * extack)1157 static int cbq_init(struct Qdisc *sch, struct nlattr *opt,
1158 struct netlink_ext_ack *extack)
1159 {
1160 struct cbq_sched_data *q = qdisc_priv(sch);
1161 struct nlattr *tb[TCA_CBQ_MAX + 1];
1162 struct tc_ratespec *r;
1163 int err;
1164
1165 qdisc_watchdog_init(&q->watchdog, sch);
1166 hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
1167 q->delay_timer.function = cbq_undelay;
1168
1169 err = cbq_opt_parse(tb, opt, extack);
1170 if (err < 0)
1171 return err;
1172
1173 if (!tb[TCA_CBQ_RTAB] || !tb[TCA_CBQ_RATE]) {
1174 NL_SET_ERR_MSG(extack, "Rate specification missing or incomplete");
1175 return -EINVAL;
1176 }
1177
1178 r = nla_data(tb[TCA_CBQ_RATE]);
1179
1180 q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB], extack);
1181 if (!q->link.R_tab)
1182 return -EINVAL;
1183
1184 err = tcf_block_get(&q->link.block, &q->link.filter_list, sch, extack);
1185 if (err)
1186 goto put_rtab;
1187
1188 err = qdisc_class_hash_init(&q->clhash);
1189 if (err < 0)
1190 goto put_block;
1191
1192 q->link.sibling = &q->link;
1193 q->link.common.classid = sch->handle;
1194 q->link.qdisc = sch;
1195 q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1196 sch->handle, NULL);
1197 if (!q->link.q)
1198 q->link.q = &noop_qdisc;
1199 else
1200 qdisc_hash_add(q->link.q, true);
1201
1202 q->link.priority = TC_CBQ_MAXPRIO - 1;
1203 q->link.priority2 = TC_CBQ_MAXPRIO - 1;
1204 q->link.cpriority = TC_CBQ_MAXPRIO - 1;
1205 q->link.allot = psched_mtu(qdisc_dev(sch));
1206 q->link.quantum = q->link.allot;
1207 q->link.weight = q->link.R_tab->rate.rate;
1208
1209 q->link.ewma_log = TC_CBQ_DEF_EWMA;
1210 q->link.avpkt = q->link.allot/2;
1211 q->link.minidle = -0x7FFFFFFF;
1212
1213 q->toplevel = TC_CBQ_MAXLEVEL;
1214 q->now = psched_get_time();
1215
1216 cbq_link_class(&q->link);
1217
1218 if (tb[TCA_CBQ_LSSOPT])
1219 cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT]));
1220
1221 cbq_addprio(q, &q->link);
1222 return 0;
1223
1224 put_block:
1225 tcf_block_put(q->link.block);
1226
1227 put_rtab:
1228 qdisc_put_rtab(q->link.R_tab);
1229 return err;
1230 }
1231
cbq_dump_rate(struct sk_buff * skb,struct cbq_class * cl)1232 static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
1233 {
1234 unsigned char *b = skb_tail_pointer(skb);
1235
1236 if (nla_put(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate))
1237 goto nla_put_failure;
1238 return skb->len;
1239
1240 nla_put_failure:
1241 nlmsg_trim(skb, b);
1242 return -1;
1243 }
1244
cbq_dump_lss(struct sk_buff * skb,struct cbq_class * cl)1245 static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
1246 {
1247 unsigned char *b = skb_tail_pointer(skb);
1248 struct tc_cbq_lssopt opt;
1249
1250 opt.flags = 0;
1251 if (cl->borrow == NULL)
1252 opt.flags |= TCF_CBQ_LSS_BOUNDED;
1253 if (cl->share == NULL)
1254 opt.flags |= TCF_CBQ_LSS_ISOLATED;
1255 opt.ewma_log = cl->ewma_log;
1256 opt.level = cl->level;
1257 opt.avpkt = cl->avpkt;
1258 opt.maxidle = cl->maxidle;
1259 opt.minidle = (u32)(-cl->minidle);
1260 opt.offtime = cl->offtime;
1261 opt.change = ~0;
1262 if (nla_put(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt))
1263 goto nla_put_failure;
1264 return skb->len;
1265
1266 nla_put_failure:
1267 nlmsg_trim(skb, b);
1268 return -1;
1269 }
1270
cbq_dump_wrr(struct sk_buff * skb,struct cbq_class * cl)1271 static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
1272 {
1273 unsigned char *b = skb_tail_pointer(skb);
1274 struct tc_cbq_wrropt opt;
1275
1276 memset(&opt, 0, sizeof(opt));
1277 opt.flags = 0;
1278 opt.allot = cl->allot;
1279 opt.priority = cl->priority + 1;
1280 opt.cpriority = cl->cpriority + 1;
1281 opt.weight = cl->weight;
1282 if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt))
1283 goto nla_put_failure;
1284 return skb->len;
1285
1286 nla_put_failure:
1287 nlmsg_trim(skb, b);
1288 return -1;
1289 }
1290
cbq_dump_fopt(struct sk_buff * skb,struct cbq_class * cl)1291 static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
1292 {
1293 unsigned char *b = skb_tail_pointer(skb);
1294 struct tc_cbq_fopt opt;
1295
1296 if (cl->split || cl->defmap) {
1297 opt.split = cl->split ? cl->split->common.classid : 0;
1298 opt.defmap = cl->defmap;
1299 opt.defchange = ~0;
1300 if (nla_put(skb, TCA_CBQ_FOPT, sizeof(opt), &opt))
1301 goto nla_put_failure;
1302 }
1303 return skb->len;
1304
1305 nla_put_failure:
1306 nlmsg_trim(skb, b);
1307 return -1;
1308 }
1309
cbq_dump_attr(struct sk_buff * skb,struct cbq_class * cl)1310 static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
1311 {
1312 if (cbq_dump_lss(skb, cl) < 0 ||
1313 cbq_dump_rate(skb, cl) < 0 ||
1314 cbq_dump_wrr(skb, cl) < 0 ||
1315 cbq_dump_fopt(skb, cl) < 0)
1316 return -1;
1317 return 0;
1318 }
1319
cbq_dump(struct Qdisc * sch,struct sk_buff * skb)1320 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
1321 {
1322 struct cbq_sched_data *q = qdisc_priv(sch);
1323 struct nlattr *nest;
1324
1325 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1326 if (nest == NULL)
1327 goto nla_put_failure;
1328 if (cbq_dump_attr(skb, &q->link) < 0)
1329 goto nla_put_failure;
1330 return nla_nest_end(skb, nest);
1331
1332 nla_put_failure:
1333 nla_nest_cancel(skb, nest);
1334 return -1;
1335 }
1336
1337 static int
cbq_dump_stats(struct Qdisc * sch,struct gnet_dump * d)1338 cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
1339 {
1340 struct cbq_sched_data *q = qdisc_priv(sch);
1341
1342 q->link.xstats.avgidle = q->link.avgidle;
1343 return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats));
1344 }
1345
1346 static int
cbq_dump_class(struct Qdisc * sch,unsigned long arg,struct sk_buff * skb,struct tcmsg * tcm)1347 cbq_dump_class(struct Qdisc *sch, unsigned long arg,
1348 struct sk_buff *skb, struct tcmsg *tcm)
1349 {
1350 struct cbq_class *cl = (struct cbq_class *)arg;
1351 struct nlattr *nest;
1352
1353 if (cl->tparent)
1354 tcm->tcm_parent = cl->tparent->common.classid;
1355 else
1356 tcm->tcm_parent = TC_H_ROOT;
1357 tcm->tcm_handle = cl->common.classid;
1358 tcm->tcm_info = cl->q->handle;
1359
1360 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1361 if (nest == NULL)
1362 goto nla_put_failure;
1363 if (cbq_dump_attr(skb, cl) < 0)
1364 goto nla_put_failure;
1365 return nla_nest_end(skb, nest);
1366
1367 nla_put_failure:
1368 nla_nest_cancel(skb, nest);
1369 return -1;
1370 }
1371
1372 static int
cbq_dump_class_stats(struct Qdisc * sch,unsigned long arg,struct gnet_dump * d)1373 cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1374 struct gnet_dump *d)
1375 {
1376 struct cbq_sched_data *q = qdisc_priv(sch);
1377 struct cbq_class *cl = (struct cbq_class *)arg;
1378 __u32 qlen;
1379
1380 cl->xstats.avgidle = cl->avgidle;
1381 cl->xstats.undertime = 0;
1382 qdisc_qstats_qlen_backlog(cl->q, &qlen, &cl->qstats.backlog);
1383
1384 if (cl->undertime != PSCHED_PASTPERFECT)
1385 cl->xstats.undertime = cl->undertime - q->now;
1386
1387 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
1388 d, NULL, &cl->bstats) < 0 ||
1389 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1390 gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
1391 return -1;
1392
1393 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1394 }
1395
cbq_graft(struct Qdisc * sch,unsigned long arg,struct Qdisc * new,struct Qdisc ** old,struct netlink_ext_ack * extack)1396 static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1397 struct Qdisc **old, struct netlink_ext_ack *extack)
1398 {
1399 struct cbq_class *cl = (struct cbq_class *)arg;
1400
1401 if (new == NULL) {
1402 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1403 cl->common.classid, extack);
1404 if (new == NULL)
1405 return -ENOBUFS;
1406 }
1407
1408 *old = qdisc_replace(sch, new, &cl->q);
1409 return 0;
1410 }
1411
cbq_leaf(struct Qdisc * sch,unsigned long arg)1412 static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg)
1413 {
1414 struct cbq_class *cl = (struct cbq_class *)arg;
1415
1416 return cl->q;
1417 }
1418
cbq_qlen_notify(struct Qdisc * sch,unsigned long arg)1419 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
1420 {
1421 struct cbq_class *cl = (struct cbq_class *)arg;
1422
1423 cbq_deactivate_class(cl);
1424 }
1425
cbq_find(struct Qdisc * sch,u32 classid)1426 static unsigned long cbq_find(struct Qdisc *sch, u32 classid)
1427 {
1428 struct cbq_sched_data *q = qdisc_priv(sch);
1429
1430 return (unsigned long)cbq_class_lookup(q, classid);
1431 }
1432
cbq_destroy_class(struct Qdisc * sch,struct cbq_class * cl)1433 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
1434 {
1435 struct cbq_sched_data *q = qdisc_priv(sch);
1436
1437 WARN_ON(cl->filters);
1438
1439 tcf_block_put(cl->block);
1440 qdisc_put(cl->q);
1441 qdisc_put_rtab(cl->R_tab);
1442 gen_kill_estimator(&cl->rate_est);
1443 if (cl != &q->link)
1444 kfree(cl);
1445 }
1446
cbq_destroy(struct Qdisc * sch)1447 static void cbq_destroy(struct Qdisc *sch)
1448 {
1449 struct cbq_sched_data *q = qdisc_priv(sch);
1450 struct hlist_node *next;
1451 struct cbq_class *cl;
1452 unsigned int h;
1453
1454 #ifdef CONFIG_NET_CLS_ACT
1455 q->rx_class = NULL;
1456 #endif
1457 /*
1458 * Filters must be destroyed first because we don't destroy the
1459 * classes from root to leafs which means that filters can still
1460 * be bound to classes which have been destroyed already. --TGR '04
1461 */
1462 for (h = 0; h < q->clhash.hashsize; h++) {
1463 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1464 tcf_block_put(cl->block);
1465 cl->block = NULL;
1466 }
1467 }
1468 for (h = 0; h < q->clhash.hashsize; h++) {
1469 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[h],
1470 common.hnode)
1471 cbq_destroy_class(sch, cl);
1472 }
1473 qdisc_class_hash_destroy(&q->clhash);
1474 }
1475
1476 static int
cbq_change_class(struct Qdisc * sch,u32 classid,u32 parentid,struct nlattr ** tca,unsigned long * arg,struct netlink_ext_ack * extack)1477 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
1478 unsigned long *arg, struct netlink_ext_ack *extack)
1479 {
1480 int err;
1481 struct cbq_sched_data *q = qdisc_priv(sch);
1482 struct cbq_class *cl = (struct cbq_class *)*arg;
1483 struct nlattr *opt = tca[TCA_OPTIONS];
1484 struct nlattr *tb[TCA_CBQ_MAX + 1];
1485 struct cbq_class *parent;
1486 struct qdisc_rate_table *rtab = NULL;
1487
1488 err = cbq_opt_parse(tb, opt, extack);
1489 if (err < 0)
1490 return err;
1491
1492 if (tb[TCA_CBQ_OVL_STRATEGY] || tb[TCA_CBQ_POLICE]) {
1493 NL_SET_ERR_MSG(extack, "Neither overlimit strategy nor policing attributes can be used for changing class params");
1494 return -EOPNOTSUPP;
1495 }
1496
1497 if (cl) {
1498 /* Check parent */
1499 if (parentid) {
1500 if (cl->tparent &&
1501 cl->tparent->common.classid != parentid) {
1502 NL_SET_ERR_MSG(extack, "Invalid parent id");
1503 return -EINVAL;
1504 }
1505 if (!cl->tparent && parentid != TC_H_ROOT) {
1506 NL_SET_ERR_MSG(extack, "Parent must be root");
1507 return -EINVAL;
1508 }
1509 }
1510
1511 if (tb[TCA_CBQ_RATE]) {
1512 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]),
1513 tb[TCA_CBQ_RTAB], extack);
1514 if (rtab == NULL)
1515 return -EINVAL;
1516 }
1517
1518 if (tca[TCA_RATE]) {
1519 err = gen_replace_estimator(&cl->bstats, NULL,
1520 &cl->rate_est,
1521 NULL,
1522 qdisc_root_sleeping_running(sch),
1523 tca[TCA_RATE]);
1524 if (err) {
1525 NL_SET_ERR_MSG(extack, "Failed to replace specified rate estimator");
1526 qdisc_put_rtab(rtab);
1527 return err;
1528 }
1529 }
1530
1531 /* Change class parameters */
1532 sch_tree_lock(sch);
1533
1534 if (cl->next_alive != NULL)
1535 cbq_deactivate_class(cl);
1536
1537 if (rtab) {
1538 qdisc_put_rtab(cl->R_tab);
1539 cl->R_tab = rtab;
1540 }
1541
1542 if (tb[TCA_CBQ_LSSOPT])
1543 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1544
1545 if (tb[TCA_CBQ_WRROPT]) {
1546 cbq_rmprio(q, cl);
1547 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1548 }
1549
1550 if (tb[TCA_CBQ_FOPT])
1551 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1552
1553 if (cl->q->q.qlen)
1554 cbq_activate_class(cl);
1555
1556 sch_tree_unlock(sch);
1557
1558 return 0;
1559 }
1560
1561 if (parentid == TC_H_ROOT)
1562 return -EINVAL;
1563
1564 if (!tb[TCA_CBQ_WRROPT] || !tb[TCA_CBQ_RATE] || !tb[TCA_CBQ_LSSOPT]) {
1565 NL_SET_ERR_MSG(extack, "One of the following attributes MUST be specified: WRR, rate or link sharing");
1566 return -EINVAL;
1567 }
1568
1569 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB],
1570 extack);
1571 if (rtab == NULL)
1572 return -EINVAL;
1573
1574 if (classid) {
1575 err = -EINVAL;
1576 if (TC_H_MAJ(classid ^ sch->handle) ||
1577 cbq_class_lookup(q, classid)) {
1578 NL_SET_ERR_MSG(extack, "Specified class not found");
1579 goto failure;
1580 }
1581 } else {
1582 int i;
1583 classid = TC_H_MAKE(sch->handle, 0x8000);
1584
1585 for (i = 0; i < 0x8000; i++) {
1586 if (++q->hgenerator >= 0x8000)
1587 q->hgenerator = 1;
1588 if (cbq_class_lookup(q, classid|q->hgenerator) == NULL)
1589 break;
1590 }
1591 err = -ENOSR;
1592 if (i >= 0x8000) {
1593 NL_SET_ERR_MSG(extack, "Unable to generate classid");
1594 goto failure;
1595 }
1596 classid = classid|q->hgenerator;
1597 }
1598
1599 parent = &q->link;
1600 if (parentid) {
1601 parent = cbq_class_lookup(q, parentid);
1602 err = -EINVAL;
1603 if (!parent) {
1604 NL_SET_ERR_MSG(extack, "Failed to find parentid");
1605 goto failure;
1606 }
1607 }
1608
1609 err = -ENOBUFS;
1610 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1611 if (cl == NULL)
1612 goto failure;
1613
1614 err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1615 if (err) {
1616 kfree(cl);
1617 return err;
1618 }
1619
1620 if (tca[TCA_RATE]) {
1621 err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1622 NULL,
1623 qdisc_root_sleeping_running(sch),
1624 tca[TCA_RATE]);
1625 if (err) {
1626 NL_SET_ERR_MSG(extack, "Couldn't create new estimator");
1627 tcf_block_put(cl->block);
1628 kfree(cl);
1629 goto failure;
1630 }
1631 }
1632
1633 cl->R_tab = rtab;
1634 rtab = NULL;
1635 cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid,
1636 NULL);
1637 if (!cl->q)
1638 cl->q = &noop_qdisc;
1639 else
1640 qdisc_hash_add(cl->q, true);
1641
1642 cl->common.classid = classid;
1643 cl->tparent = parent;
1644 cl->qdisc = sch;
1645 cl->allot = parent->allot;
1646 cl->quantum = cl->allot;
1647 cl->weight = cl->R_tab->rate.rate;
1648
1649 sch_tree_lock(sch);
1650 cbq_link_class(cl);
1651 cl->borrow = cl->tparent;
1652 if (cl->tparent != &q->link)
1653 cl->share = cl->tparent;
1654 cbq_adjust_levels(parent);
1655 cl->minidle = -0x7FFFFFFF;
1656 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT]));
1657 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT]));
1658 if (cl->ewma_log == 0)
1659 cl->ewma_log = q->link.ewma_log;
1660 if (cl->maxidle == 0)
1661 cl->maxidle = q->link.maxidle;
1662 if (cl->avpkt == 0)
1663 cl->avpkt = q->link.avpkt;
1664 if (tb[TCA_CBQ_FOPT])
1665 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT]));
1666 sch_tree_unlock(sch);
1667
1668 qdisc_class_hash_grow(sch, &q->clhash);
1669
1670 *arg = (unsigned long)cl;
1671 return 0;
1672
1673 failure:
1674 qdisc_put_rtab(rtab);
1675 return err;
1676 }
1677
cbq_delete(struct Qdisc * sch,unsigned long arg)1678 static int cbq_delete(struct Qdisc *sch, unsigned long arg)
1679 {
1680 struct cbq_sched_data *q = qdisc_priv(sch);
1681 struct cbq_class *cl = (struct cbq_class *)arg;
1682
1683 if (cl->filters || cl->children || cl == &q->link)
1684 return -EBUSY;
1685
1686 sch_tree_lock(sch);
1687
1688 qdisc_purge_queue(cl->q);
1689
1690 if (cl->next_alive)
1691 cbq_deactivate_class(cl);
1692
1693 if (q->tx_borrowed == cl)
1694 q->tx_borrowed = q->tx_class;
1695 if (q->tx_class == cl) {
1696 q->tx_class = NULL;
1697 q->tx_borrowed = NULL;
1698 }
1699 #ifdef CONFIG_NET_CLS_ACT
1700 if (q->rx_class == cl)
1701 q->rx_class = NULL;
1702 #endif
1703
1704 cbq_unlink_class(cl);
1705 cbq_adjust_levels(cl->tparent);
1706 cl->defmap = 0;
1707 cbq_sync_defmap(cl);
1708
1709 cbq_rmprio(q, cl);
1710 sch_tree_unlock(sch);
1711
1712 cbq_destroy_class(sch, cl);
1713 return 0;
1714 }
1715
cbq_tcf_block(struct Qdisc * sch,unsigned long arg,struct netlink_ext_ack * extack)1716 static struct tcf_block *cbq_tcf_block(struct Qdisc *sch, unsigned long arg,
1717 struct netlink_ext_ack *extack)
1718 {
1719 struct cbq_sched_data *q = qdisc_priv(sch);
1720 struct cbq_class *cl = (struct cbq_class *)arg;
1721
1722 if (cl == NULL)
1723 cl = &q->link;
1724
1725 return cl->block;
1726 }
1727
cbq_bind_filter(struct Qdisc * sch,unsigned long parent,u32 classid)1728 static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent,
1729 u32 classid)
1730 {
1731 struct cbq_sched_data *q = qdisc_priv(sch);
1732 struct cbq_class *p = (struct cbq_class *)parent;
1733 struct cbq_class *cl = cbq_class_lookup(q, classid);
1734
1735 if (cl) {
1736 if (p && p->level <= cl->level)
1737 return 0;
1738 cl->filters++;
1739 return (unsigned long)cl;
1740 }
1741 return 0;
1742 }
1743
cbq_unbind_filter(struct Qdisc * sch,unsigned long arg)1744 static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
1745 {
1746 struct cbq_class *cl = (struct cbq_class *)arg;
1747
1748 cl->filters--;
1749 }
1750
cbq_walk(struct Qdisc * sch,struct qdisc_walker * arg)1751 static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1752 {
1753 struct cbq_sched_data *q = qdisc_priv(sch);
1754 struct cbq_class *cl;
1755 unsigned int h;
1756
1757 if (arg->stop)
1758 return;
1759
1760 for (h = 0; h < q->clhash.hashsize; h++) {
1761 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) {
1762 if (arg->count < arg->skip) {
1763 arg->count++;
1764 continue;
1765 }
1766 if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1767 arg->stop = 1;
1768 return;
1769 }
1770 arg->count++;
1771 }
1772 }
1773 }
1774
1775 static const struct Qdisc_class_ops cbq_class_ops = {
1776 .graft = cbq_graft,
1777 .leaf = cbq_leaf,
1778 .qlen_notify = cbq_qlen_notify,
1779 .find = cbq_find,
1780 .change = cbq_change_class,
1781 .delete = cbq_delete,
1782 .walk = cbq_walk,
1783 .tcf_block = cbq_tcf_block,
1784 .bind_tcf = cbq_bind_filter,
1785 .unbind_tcf = cbq_unbind_filter,
1786 .dump = cbq_dump_class,
1787 .dump_stats = cbq_dump_class_stats,
1788 };
1789
1790 static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
1791 .next = NULL,
1792 .cl_ops = &cbq_class_ops,
1793 .id = "cbq",
1794 .priv_size = sizeof(struct cbq_sched_data),
1795 .enqueue = cbq_enqueue,
1796 .dequeue = cbq_dequeue,
1797 .peek = qdisc_peek_dequeued,
1798 .init = cbq_init,
1799 .reset = cbq_reset,
1800 .destroy = cbq_destroy,
1801 .change = NULL,
1802 .dump = cbq_dump,
1803 .dump_stats = cbq_dump_stats,
1804 .owner = THIS_MODULE,
1805 };
1806
cbq_module_init(void)1807 static int __init cbq_module_init(void)
1808 {
1809 return register_qdisc(&cbq_qdisc_ops);
1810 }
cbq_module_exit(void)1811 static void __exit cbq_module_exit(void)
1812 {
1813 unregister_qdisc(&cbq_qdisc_ops);
1814 }
1815 module_init(cbq_module_init)
1816 module_exit(cbq_module_exit)
1817 MODULE_LICENSE("GPL");
1818
